Loudspeaker, mobile device and method of manufacturing a loudspeaker

ABSTRACT

A loudspeaker comprises an enclosure, at least one dynamic driver mounted in the enclosure, and at least one porous monolithic block. The at least one porous monolithic block comprises a plurality of pores and is mounted within the enclosure.

BACKGROUND OF THE INVENTION Field of the Invention

The invention relates to a loudspeaker and to a method of manufacturinga loudspeaker. The invention also relates to a mobile device, such as amobile phone, comprising a loudspeaker.

Related Prior Art

European patent No. 2 424 270 B1 discloses a loudspeaker which comprisesan enclosure and a dynamic driver mounted in the enclosure. Theenclosure is filled with a zeolite material. Filling the enclosure withthe zeolite material results in in an apparent virtual enlargement ofthe volume defined by the enclosure, i.e. results in increasing theeffective volume of the enclosure. The zeolite material comprises grainshaving an average grain size in a range between 0.2 and 0.9 mm andhaving a plurality of zeolite particles adhered together by means of abinder. The zeolite particles comprise pores and have a silicon toaluminum mass ration of at least 200.

SUMMARY OF THE INVENTION

It is an object of the present invention to provide a loudspeakercomprised of an enclosure and a dynamic driver mounted in the enclosure,which loudspeaker can be manufactured more easily.

The object of the invention is achieved by means of a loudspeaker,comprising an enclosure; at least one dynamic driver mounted in theenclosure; and at least one porous monolithic block mounted within theenclosure.

A further aspect of the invention relates to a method of manufacturingthe loudspeaker according to the invention, comprising the steps of:

-   -   providing a plurality of particles;    -   producing the at least one porous monolithic block utilizing the        plurality of particles; and    -   mounting the porous monolithic block into the enclosure.

Another aspect of the invention relates to a mobile device comprising aloudspeaker according to the invention. The mobile device is, forinstance, a mobile telephone.

Yet another aspect of the invention relates to a method of producing themobile device according to the invention, comprising the steps of:

-   -   providing a plurality of particles;    -   producing the at least one porous monolithic block; and    -   mounting the porous monolithic block into the enclosure.

The loudspeaker comprises the enclosure. The enclosure is preferably asealed enclosure. Sealed loudspeaker enclosures are also referred to asclosed enclosures.

The loudspeaker comprises at least one dynamic driver. Dynamic driversper se are known to the skilled person. Dynamic drivers usually comprisea magnet system, a membrane movably mounted with respect to the magnetsystem, and a voice coil attached to the membrane. The magnet systemcomprises a magnet and the voice coil is operatively coupled with themagnet. When applying an electric signal to the voice coil, forinstance, generated by an amplifier, then the membrane moves in responseto the electric signal. The electric signal is, for instance, anelectric voltage.

The enclosure provides a volume, specifically a back volume for thedynamic driver.

The loudspeaker further comprises the at least one porous monolithicblock which is mounted within the enclosure. Thus, the at least onemonolithic block is placed within the back volume for the dynamicdriver.

Particularly, the porous monolithic block comprises a plurality of firstpores. Preferably, the first pores have a size or diameter between 0.7μm and 30 μm. Inter alia due to the first pores, the effective volume ofthe loudspeaker, i.e. the effective back volume for the dynamic driveris greater than the back volume for the dynamic driver without the atleast one porous monolithic block, resulting in a potential increasedsound quality of the entire loudspeaker. Particularly, due to the atleast one porous monolithic block, a resonance frequency of the entireloudspeaker may be reduced compared to the resonance frequency of theentire loudspeaker without the at least one porous monolithic block.Therefore, it may be possible to reduce the overall volume of theloudspeaker or its enclosure, respectively, allowing to manufacture arelatively small loudspeaker especially having an improved or at leastan acceptable sound quality when, for instance, using it for a mobiledevice, such as a mobile phone.

The porous monolithic block may be made from any suitable material.Preferably, the porous monolithic block comprises a zeolite material.The porous monolithic block may even consist of a zeolite material.

There may only a single porous monolithic block be mounted within theenclosure.

The enclosure may comprise a plurality of sub-enclosures acousticallycoupled to each other and, thus, forming the enclosure. The at least oneporous monolithic block may be mounted within at least one of thesub-enclosures. For instance, in one or at least in some of thesub-enclosures may be mounted each a single porous monolithic block. Itmay also be possible that one of the sub-enclosures is associated withthe dynamic driver, i.e. that the dynamic driver is mounted in one ofthe sub-enclosures. Then, the sub-enclosure associated with the dynamicdriver may be empty, while the at least one porous monolithic block ismounted within at least one of the remaining sub-enclosures.

The at least one porous monolithic block may be adapted to the shape ofthe enclosure or to the shape of the relevant at least onesub-enclosure, respectively. Particularly, the enclosure may have acontour and the at least one porous monolithic block may be mounted intothe enclosure in a form-fit manner corresponding to the contour of theenclosure. If the enclosure comprises the plurality of sub-enclosures,then the at least one porous monolithic block may be mounted into therelevant sub-enclosure in a form-fit manner corresponding to the contourof that sub-enclosure.

The at least one porous monolithic block may be produced using afreezing casting method using a plurality of particles. Alternatively,the at least one porous monolithic block may be produced by a freezingfoaming method using the plurality of particles, a sintering methodusing the plurality of particles, a ceramic foaming method using theplurality of particles, or a self-curing binding technique using theplurality of particles. The particles are preferably porous particleshaving second pores. Preferably, the size of the second pores may differfrom the size of the first pores. The second pores may have a size ordiameter of less than 1 nm. When utilizing the porous particles forproducing the porous monolithic block, then the porous monolithic blockmay comprise the first pores and at least some of the second pores ofthe porous particles.

For the aforementioned methods, an appropriate mold may be used. Thecontour of the mold may correspond to the contour of the enclosure or tothe relevant sub-enclosure, respectively, in order to produce a porousmonolithic block having a shape adapted to the shape of the enclosure orthe relevant sub-enclosure, or whose contour matches the contour of theenclosure or the relevant sub-enclosure for the form-fit mounting.

For instance, if the at least one porous monolithic block is madeutilizing the freezing casting method, then the mold may at least partlybe made from PTFE (Polytetrafluorethylen).

For instance, if the porous monolithic block is made utilizing thefreezing foaming method, then the mold may at least partly be made fromsilicon rubber.

The particles or the porous particles may be any suitable organic orinorganic particles or porous particles, respectively. Preferably, theparticles may be zeolite particles. The porous particles may be porouszeolite particles.

Especially, the porous particles form a zeolite powder. In particular,the zeolite particles are similar or equal those published by Europeanapplication for patent No. 2 424 270 which is entirely incorporated byreference. The zeolite particles may have diameters of 10 μm in diameteror smaller.

Contrary to the method disclosed by European application for patent No.2 424 270 the particles are not used for producing a plurality ofgrains, however, according to embodiments of the invention, to producethe at least one porous monolithic block.

The at least one porous monolithic block may be produced by providing anappropriate binder and a mold whose contour corresponds to the contourof the enclosure or the relevant sub-enclosure. Then, the binder and theplurality of particles may be mixed and this mixture may be filled intothe mold. Then, the mold filled with the mixture of the plurality ofparticles and the binder is frozen in order to produce the at least oneporous monolithic block. Then, the mold is removed from the porousmonolithic block. This method basically describes a freezing castingmethod.

The at least one porous monolithic block may be produced by providing anappropriate binder and a mold whose contour corresponds to the contourof the enclosure or the relevant sub-enclosure. Then, the binder and theplurality of particles may be mixed and this mixture may be filled intothe mold. Then, the ambient pressure around the mold filled with themixture of the plurality of particles and the binder is reduced in orderto produce the porous monolithic block. Then, the mold is removed fromthe porous monolithic block. This method basically describes a freezingfoaming method.

The at least one porous monolithic block may be produced by providing anappropriate binder and a mold whose contour corresponds to the contourof the enclosure or the relevant sub-enclosure. Then, the binder and theplurality of particles may be mixed and this mixture may be filled intothe mold. Then, the mold filled with the mixture of the plurality ofparticles and the binder is heated in order to produce the relevantporous monolithic block. During the heating, the binder burns at leastpartially. For example, two different kinds of binders may be used. Onetype of binder may be a temporary binder which burns completely oralmost completely during the heating creating the first pores. Anothertype of binder may not burn during the heating. Then, the mold isremoved from the porous monolithic block. This method basicallydescribes a sintering method. Alternatively, the foaming of theplurality of particles can also be achieved by a ceramic foaming method.

The at least one porous monolithic block may be produced by providing aprotein foam as a structuring agent, an appropriate binder and a moldwhose contour corresponds to the contour of the enclosure or therelevant sub-enclosure. Then, the protein foam, the binder and theplurality of particles may be mixed and this mixture may be filled intothe mold. Then, one has to wait until the mixture filled into the moldself-cures in order to produce the porous monolithic block. Then, themold is removed from the porous monolithic block. This method basicallydescribes a self-curing binding method.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a top view of a mobile phone;

FIG. 2 is a top view of a loudspeaker comprising monolithic blocks, adynamic driver and an enclosure which is shown open;

FIG. 3 is a top view of the opened enclosure;

FIG. 4 are the monolithic blocks;

FIG. 5 is a plurality of particles;

FIG. 6 is a mold; and

FIG. 7 is a flow chart.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

FIG. 1 shows a mobile phone 1 as an example of a mobile device. Themobile phone 1 may comprise a microphone, a wireless sender-receiverunit, an amplifier and a central processing unit connected to thewireless sender-receiver unit and to the amplifier.

The mobile device 1 comprises a loudspeaker 21 which is shown in FIG. 2. The amplifier of the mobile phone 1 may be connected to theloudspeaker 21.

The loudspeaker 21 comprises at least one dynamic driver 22. Dynamicdrivers per se are known to the skilled person. Dynamic drivers usuallycomprise a magnet system, a membrane movably mounted with respect to themagnet system, and a voice coil attached to the membrane. The magnetsystem comprises a magnet and the voice coil is operatively coupled withthe magnet. When applying an electric signal to the voice coil, forinstance, generated by the amplifier, then the membrane moves inresponse to the electric signal.

The loudspeaker 21 comprises an enclosure 23 and at least one porousmonolithic block mounted within the enclosure 23. In particular, theloudspeaker 21 comprises a first porous monolithic block 24 a and asecond porous monolithic block 24 b.

FIG. 2 shows in particular a top view of the of the loudspeaker 21 withits enclosure 23 opened. FIG. 3 shows a top view of the opened enclosure23 and FIG. 4 shows the porous monolithic blocks 24 a, 24 b.

In the present embodiment, the enclosure 23 comprises a plurality ofsub-enclosures, namely a first sub-enclosure 23 a, a secondsub-enclosure 23 b, and a third sub-enclosure 23 c. The sub-enclosures23 a, 23 b, 23 c are acoustically coupled to each other and form, as aresult, the single enclosure 23 for the dynamic driver 22.

In the present embodiment, the enclosure 23 is a sealed enclosure.Sealed enclosures are also known as closed enclosures.

The dynamic driver 22 is mounted in the third sub-enclosure 23 c. Inparticular, the third sub-enclosure 23 c comprises an aperture 25 inwhich the dynamic driver 22 is mounted.

The porous monolithic blocks 24 a, 24 b are mounted within the enclosure23. In the present embodiment, the first porous monolithic block 24 a ismounted within the first sub-enclosure 23 a, and the second porousmonolithic block 24 b is mounted within the second sub-enclosure 23 b.

The first and second sub-enclosures 23 a, 23 b may be identical or, asshown in the figures, may differ from each other.

The porous monolithic blocks 24 a, 24 b each comprise first pores 27.Particularly, the first pores 27 have a diameter between 0.7 μm to 30μm.

Preferably, the porous monolithic blocks 23 a, 23 b comprise each azeolite material. Due to the porous monolithic blocks 24 a, 24 b, theeffective volume of the enclosure 23 is greater than the volume of theenclosure 23 without the porous monolithic blocks 24 a, 24 b.

The porous monolithic blocks 24 a, 24 b may be produced using a freezingcasting method using a plurality of porous particles 51 shown in FIG. 5. Alternatively, the monolithic blocks 24 a, 24 b may be produced by afreezing foaming method using the plurality of porous particles 51, asintering method using the plurality of porous particles 51, a ceramicfoaming method using the plurality of porous particles 51, or aself-curing binding technique using the plurality of porous particles51. The porous particles 51 comprise second pores 28. The size ordiameter of the second pores 51 are preferably less than 1 nm.

For the aforementioned methods, an appropriate mold 61, as shown in FIG.6 , may be used. Particularly, the mold 61 is made from a materialappropriate for the specific method. In particular, each porousmonolithic block 24 a, 24 b may be made utilizing an individual mold 61.

For instance, if the porous monolithic blocks 24 a, 24 b are madeutilizing the freezing casting method, then the mold 61 may at leastpartly be made from PTFE (Polytetrafluorethylen).

For instance, if the porous monolithic blocks 24 a, 24 b are madeutilizing the freezing foaming method, then the mold 61 may at leastpartly be made from silicon rubber.

Preferably, the porous particles 51 are comprised or consist of aplurality of porous zeolite particles.

In the present embodiment, the shape of the first and secondsub-enclosures 23 a, 23 b differ.

In particular, the shape of the porous monolithic block 24 a, 24 b areadapted to the shape of the relevant sub-enclosures 23 a, 23 b, i.e. theshape of the first porous monolithic block 24 a is adapted to the shapeof the first sub-enclosure 23 a, and the shape of the second porousmonolithic block 24 b is adapted to the shape of the secondsub-enclosure 23 b. When using one of the aforementioned methods toproduce the porous monolithic blocks 24 a, 24 b, then, for instance, themold 61 can be adapted to the shape of the relevant sub-enclosure 23 a,23 b.

The enclosure 23 may have a contour. More specifically, the surface ofthe enclosure 23 facing towards the porous monolithic blocks 24 a, 24 bmay have the contour. Preferably, the porous monolithic blocks 24 a, 24b are mounted into the enclosure 23 in a form-fit manner correspondingto the contour of the enclosure 23.

In the present embodiment, the first sub-enclosure 23 a has a firstcontour 26 a and the second sub-enclosure 23 b has a second contour 26b. Preferably, the first porous monolithic block 24 a is mounted intothe first sub-enclosure 23 a in a form-fit manner corresponding to thefirst contour 26 a of the first sub-enclosure 23 a, and the secondporous monolithic block 24 b is mounted into the second sub-enclosure 23b in a form-fit manner corresponding to the second contour 26 b of thesecond sub-enclosure 23 b.

When using one of the aforementioned methods to produce the porousmonolithic blocks 24 a, 24 b, then, for instance, each porous monolithicblock 34 a, 24 b is made using its specific mold 61. These molds 61 maypreferably each have a contour 62 which corresponds to the contour 26 a,26 b of the relevant sub-enclosure 23 a, 23 b.

FIG. 7 summarize, by means of a flow chart, embodiments how tomanufacture the loudspeaker 21 and the mobile phone 1, respectively.

For manufacturing the loudspeaker 21 or the mobile device 1, theplurality of particles 51 may be provided, step A of the flow chart.

Then, the porous monolithic blocks 24 a, 24 b are produced by utilizingthe plurality of particles 51, step B of the flow chart, particularly bymeans of one of the aforementioned methods and particularly by means ofthe mold 61.

Then, the porous monolithic blocks 24 a, 24 b are mounted into theenclosure 23, particularly into the first and second sub-enclosures 23a, 23 b, step C of the flow chart.

If utilizing, for instance, the freezing casting method, then the porousmonolithic blocks 24 a, 24 b may be made by providing an appropriatebinder for a freezing casting method, and the mold 61 whose contour 62corresponds to the contour 26 a, 26 b of the first and secondsub-enclosure 23 a, 23 b. Then, the binder and the plurality ofparticles 51 may be mixed and this mixture may be filled into the mold61. Then, the mold 61 filled with the mixture of the plurality ofparticles 51 and the binder is frozen in order to produce the relevantmonolithic block 24 a, 24 b. Then, the mold 61 is removed from theporous monolithic block 24 a, 24 b.

If utilizing, for instance, the freezing foaming method, then the porousmonolithic blocks may be made by providing an appropriate binder for afreezing foaming method, the mold 61 whose contour 62 corresponds to thecontour 26 a, 26 b of the first and second sub-enclosure 23 a, 23 b.Then, the binder and the plurality of particles 51 may be mixed and thismixture may be filled into the mold 61. Then, the ambient pressurearound the mold 61 filled with the mixture of the plurality of particles51 and the binder is reduced in order to produce the relevant porousmonolithic block 24 a, 24 b. Then, the mold 61 is removed from theporous monolithic block 24 a, 24 b.

If utilizing, for instance, the sintering method, then the porousmonolithic blocks 24 a, 24 b may be made by providing an appropriatebinder for a sintering method, and the mold 61 whose contour 62corresponds to the contour 26 a, 26 b of the first and secondsub-enclosure 23 a, 23 b. Then, the binder and the plurality ofparticles 51 may be mixed and this mixture may be filled into the mold61. Then, the mold 61 filled with the mixture of the plurality ofparticles 51 and the binder is heated in order to produce the relevantporous monolithic block 24 a, 24 b. During the heating, the binder burnsat least partially. For example, two different kinds of binders may beused. One type of binder is a temporary binder which burns during theheating creating the first pores 27. Another type of binder may not burnduring the heating. Then, the mold 61 is removed from the porousmonolithic block 24 a, 24 b. Alternatively, the foaming of the pluralityof particles 51 can also be achieved by a ceramic foaming method.

If utilizing, for instance, the self-curing binding method, then theporous monolithic blocks 24 a, 24 b may be made by providing a proteinfoam as a structuring agent, an appropriate binder, and the mold 61whose contour 62 corresponds to the contour 26 a, 26 b of the first andsecond sub-enclosure 23 a, 23 b. Then, the protein foam, the binder andthe plurality of particles 51 may be mixed and this mixture may befilled into the mold 61. Then, one has to wait until the mixture filledinto the mold 61 self-cures in order to produce the relevant porousmonolithic block 24 a, 24 b. Then, the mold 61 is removed from theporous monolithic block 24 a, 24 b.

Although modifications and changes may be suggested by those skilled inthe art, it is the intention of the invention to embody within thepatent warranted hereon all changes and modifications as reasonably andproperly come within the scope of his contribution to the art.

What is claimed is:
 1. A loudspeaker, comprising an enclosure; at leastone dynamic driver mounted in the enclosure; and at least one porousmonolithic block mounted within the enclosure, wherein at least one ofthe porous monolithic block comprises first pores having a diameterbetween 0.7 μm to 30 μm, wherein the enclosure comprises a plurality ofsub-enclosures acoustically coupled to each other, the at least oneporous monolithic block being mounted within at least one of thesub-enclosures.
 2. The loudspeaker of claim 1, the shape of the at leastone porous monolithic block being adapted to the shape of the enclosure.3. The loudspeaker of claim 1, the enclosure having a contour and the atleast one porous monolithic block being mounted into the enclosure in aform-fit manner corresponding to the contour of the enclosure.
 4. Theloudspeaker of claim 1, wherein the at least one porous monolithic blockcomprises a zeolite material.
 5. A mobile device, comprising theloudspeaker of claim 1.